What to check before installing a split system air conditioner

Measure the room and think about how it is used

Unit capacity should suit the space. Measure the length, width and ceiling height of the room, and note anything that affects heat: large west-facing windows, open-plan areas that flow into other rooms, insulation and whether it is upstairs.

Take these details with you when comparing units. Retailers and installers can then recommend a size rather than guessing.

Choose sensible positions for both units

Walk around inside and outside to find positions that work:

• Indoor unit: high on a wall with clear airflow, not blowing directly onto a bed or couch.
• Outdoor unit: on a stable base with room for airflow and servicing, away from bedroom windows if noise is a concern.
• Distance: shorter runs between indoor and outdoor units are generally simpler.
• Drainage: think about where condensation water will go.
• Neighbours: consider noise and airflow near shared fences.

Check your switchboard and power supply

Most split systems need their own dedicated circuit. In older homes with limited space or old fuses, the switchboard may need work first. If you are not sure what you have, the switchboard warning signs guide explains what to look out for.

Your electrician will confirm capacity and whether any changes are needed. Planning more than one unit? Mention it upfront, as it can affect the approach.

Think about running costs and comfort

Where and how you use a split system affects how comfortable it feels. Units placed to blow along the length of a room usually spread air more evenly than ones aimed at a nearby wall. Closing doors to rooms you are not cooling, using blinds on hot afternoons and keeping filters clean as the manufacturer recommends can all help the system work less hard.

If you are cooling several rooms, ask whether one larger unit or separate units in key rooms would suit your household better. There is no single right answer: it depends on your layout and how you live. Write down which rooms you most need cool on a hot night, as that is often the most useful starting point for the conversation.

Questions to ask before you book

A clear quote avoids surprises. Ask:

• Does the quote include the electrical connection and a dedicated circuit?
• Is any switchboard work needed?
• Where exactly will both units and the pipe run go?
• What happens to the old unit if one is being replaced?

Getting it installed

Our split system air conditioning page explains how we install systems for homes across the northern suburbs. If your home also needs a switchboard upgrade, we can quote both together. Homeowners in Diamond Creek, Plenty Valley and Templestowe often plan installs ahead of summer.

Frequently asked questions